This series contains a pile of patches that was created to support hooking up the AUO B116XAK01 panel to the eDP side of the bridge. In general it should be useful for hooking up a wider variety of DP panels to the bridge, especially those with lower resolution and lower bits per pixel.
The overall result of this series: * Allows panels with fewer than 4 DP lanes hooked up to work. * Optimizes the link rate for panels with 6 bpp. * Supports trying more than one link rate when training if the main link rate didn't work. * Avoids invalid link rates.
It's not expected that this series will break any existing users but testing is always good.
To support the AUO B116XAK01, we could actually stop at the ("Use 18-bit DP if we can") patch since that causes the panel to run at a link rate of 1.62 which works. The patches to try more than one link rate were all developed prior to realizing that I could just use 18-bit mode and were validated with that patch reverted.
These patches were tested on sdm845-cheza atop mainline as of 2019-12-13 and also on another board (the one with AUO B116XAK01) atop a downstream kernel tree.
This patch series doesn't do anything to optimize the MIPI link and only focuses on the DP link. For instance, it's left as an exercise to the reader to see if we can use the 666-packed mode on the MIPI link and save some power (because we could lower the clock rate).
I am nowhere near a display expert and my knowledge of DP and MIPI is pretty much zero. If something about this patch series smells wrong, it probably is. Please let know and I'll try to fix it.
Changes in v3: - Init rate_valid table, don't rely on stack being 0 (oops). - Rename rate_times_200khz to rate_per_200khz. - Loop over the ti_sn_bridge_dp_rate_lut table, making code smaller. - Use 'true' instead of 1 for bools. - Added note to commit message noting DP 1.4+ isn't well tested.
Changes in v2: - Squash in maybe-uninitialized fix from Rob Clark. - Patch ("Avoid invalid rates") replaces ("Skip non-standard DP rates")
Douglas Anderson (9): drm/bridge: ti-sn65dsi86: Split the setting of the dp and dsi rates drm/bridge: ti-sn65dsi86: zero is never greater than an unsigned int drm/bridge: ti-sn65dsi86: Don't use MIPI variables for DP link drm/bridge: ti-sn65dsi86: Config number of DP lanes Mo' Betta drm/bridge: ti-sn65dsi86: Read num lanes from the DP sink drm/bridge: ti-sn65dsi86: Use 18-bit DP if we can drm/bridge: ti-sn65dsi86: Group DP link training bits in a function drm/bridge: ti-sn65dsi86: Train at faster rates if slower ones fail drm/bridge: ti-sn65dsi86: Avoid invalid rates
drivers/gpu/drm/bridge/ti-sn65dsi86.c | 259 +++++++++++++++++++++----- 1 file changed, 216 insertions(+), 43 deletions(-)
These two things were in one function. Split into two. This looks like it's duplicating some code, but don't worry. This is is just in preparation for future changes.
This is intended to have zero functional change and will just make future patches easier to understand.
Signed-off-by: Douglas Anderson dianders@chromium.org Tested-by: Rob Clark robdclark@gmail.com Reviewed-by: Rob Clark robdclark@gmail.com ---
Changes in v3: None Changes in v2: None
drivers/gpu/drm/bridge/ti-sn65dsi86.c | 33 +++++++++++++++++++-------- 1 file changed, 23 insertions(+), 10 deletions(-)
diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c index 43abf01ebd4c..2fb9370a76e6 100644 --- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c +++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c @@ -417,6 +417,24 @@ static void ti_sn_bridge_set_refclk_freq(struct ti_sn_bridge *pdata) REFCLK_FREQ(i)); }
+static void ti_sn_bridge_set_dsi_rate(struct ti_sn_bridge *pdata) +{ + unsigned int bit_rate_mhz, clk_freq_mhz; + unsigned int val; + struct drm_display_mode *mode = + &pdata->bridge.encoder->crtc->state->adjusted_mode; + + /* set DSIA clk frequency */ + bit_rate_mhz = (mode->clock / 1000) * + mipi_dsi_pixel_format_to_bpp(pdata->dsi->format); + clk_freq_mhz = bit_rate_mhz / (pdata->dsi->lanes * 2); + + /* for each increment in val, frequency increases by 5MHz */ + val = (MIN_DSI_CLK_FREQ_MHZ / 5) + + (((clk_freq_mhz - MIN_DSI_CLK_FREQ_MHZ) / 5) & 0xFF); + regmap_write(pdata->regmap, SN_DSIA_CLK_FREQ_REG, val); +} + /** * LUT index corresponds to register value and * LUT values corresponds to dp data rate supported @@ -426,22 +444,16 @@ static const unsigned int ti_sn_bridge_dp_rate_lut[] = { 0, 1620, 2160, 2430, 2700, 3240, 4320, 5400 };
-static void ti_sn_bridge_set_dsi_dp_rate(struct ti_sn_bridge *pdata) +static void ti_sn_bridge_set_dp_rate(struct ti_sn_bridge *pdata) { - unsigned int bit_rate_mhz, clk_freq_mhz, dp_rate_mhz; - unsigned int val, i; + unsigned int bit_rate_mhz, dp_rate_mhz; + unsigned int i; struct drm_display_mode *mode = &pdata->bridge.encoder->crtc->state->adjusted_mode;
/* set DSIA clk frequency */ bit_rate_mhz = (mode->clock / 1000) * mipi_dsi_pixel_format_to_bpp(pdata->dsi->format); - clk_freq_mhz = bit_rate_mhz / (pdata->dsi->lanes * 2); - - /* for each increment in val, frequency increases by 5MHz */ - val = (MIN_DSI_CLK_FREQ_MHZ / 5) + - (((clk_freq_mhz - MIN_DSI_CLK_FREQ_MHZ) / 5) & 0xFF); - regmap_write(pdata->regmap, SN_DSIA_CLK_FREQ_REG, val);
/* set DP data rate */ dp_rate_mhz = ((bit_rate_mhz / pdata->dsi->lanes) * DP_CLK_FUDGE_NUM) / @@ -510,7 +522,8 @@ static void ti_sn_bridge_enable(struct drm_bridge *bridge) val);
/* set dsi/dp clk frequency value */ - ti_sn_bridge_set_dsi_dp_rate(pdata); + ti_sn_bridge_set_dsi_rate(pdata); + ti_sn_bridge_set_dp_rate(pdata);
/* enable DP PLL */ regmap_write(pdata->regmap, SN_PLL_ENABLE_REG, 1);
On Wed 18 Dec 14:35 PST 2019, Douglas Anderson wrote:
These two things were in one function. Split into two. This looks like it's duplicating some code, but don't worry. This is is just in preparation for future changes.
This is intended to have zero functional change and will just make future patches easier to understand.
Signed-off-by: Douglas Anderson dianders@chromium.org Tested-by: Rob Clark robdclark@gmail.com Reviewed-by: Rob Clark robdclark@gmail.com
Reviewed-by: Bjorn Andersson bjorn.andersson@linaro.org
Regards, Bjorn
Changes in v3: None Changes in v2: None
drivers/gpu/drm/bridge/ti-sn65dsi86.c | 33 +++++++++++++++++++-------- 1 file changed, 23 insertions(+), 10 deletions(-)
diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c index 43abf01ebd4c..2fb9370a76e6 100644 --- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c +++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c @@ -417,6 +417,24 @@ static void ti_sn_bridge_set_refclk_freq(struct ti_sn_bridge *pdata) REFCLK_FREQ(i)); }
+static void ti_sn_bridge_set_dsi_rate(struct ti_sn_bridge *pdata) +{
- unsigned int bit_rate_mhz, clk_freq_mhz;
- unsigned int val;
- struct drm_display_mode *mode =
&pdata->bridge.encoder->crtc->state->adjusted_mode;- /* set DSIA clk frequency */
- bit_rate_mhz = (mode->clock / 1000) *
mipi_dsi_pixel_format_to_bpp(pdata->dsi->format);- clk_freq_mhz = bit_rate_mhz / (pdata->dsi->lanes * 2);
- /* for each increment in val, frequency increases by 5MHz */
- val = (MIN_DSI_CLK_FREQ_MHZ / 5) +
(((clk_freq_mhz - MIN_DSI_CLK_FREQ_MHZ) / 5) & 0xFF);- regmap_write(pdata->regmap, SN_DSIA_CLK_FREQ_REG, val);
+}
/**
- LUT index corresponds to register value and
- LUT values corresponds to dp data rate supported
@@ -426,22 +444,16 @@ static const unsigned int ti_sn_bridge_dp_rate_lut[] = { 0, 1620, 2160, 2430, 2700, 3240, 4320, 5400 };
-static void ti_sn_bridge_set_dsi_dp_rate(struct ti_sn_bridge *pdata) +static void ti_sn_bridge_set_dp_rate(struct ti_sn_bridge *pdata) {
- unsigned int bit_rate_mhz, clk_freq_mhz, dp_rate_mhz;
- unsigned int val, i;
unsigned int bit_rate_mhz, dp_rate_mhz;
unsigned int i; struct drm_display_mode *mode = &pdata->bridge.encoder->crtc->state->adjusted_mode;
/* set DSIA clk frequency */ bit_rate_mhz = (mode->clock / 1000) * mipi_dsi_pixel_format_to_bpp(pdata->dsi->format);
clk_freq_mhz = bit_rate_mhz / (pdata->dsi->lanes * 2);
/* for each increment in val, frequency increases by 5MHz */
val = (MIN_DSI_CLK_FREQ_MHZ / 5) +
(((clk_freq_mhz - MIN_DSI_CLK_FREQ_MHZ) / 5) & 0xFF);regmap_write(pdata->regmap, SN_DSIA_CLK_FREQ_REG, val);
/* set DP data rate */ dp_rate_mhz = ((bit_rate_mhz / pdata->dsi->lanes) * DP_CLK_FUDGE_NUM) /
@@ -510,7 +522,8 @@ static void ti_sn_bridge_enable(struct drm_bridge *bridge) val);
/* set dsi/dp clk frequency value */
- ti_sn_bridge_set_dsi_dp_rate(pdata);
ti_sn_bridge_set_dsi_rate(pdata);
ti_sn_bridge_set_dp_rate(pdata);
/* enable DP PLL */ regmap_write(pdata->regmap, SN_PLL_ENABLE_REG, 1);
-- 2.24.1.735.g03f4e72817-goog
When we iterate over ti_sn_bridge_dp_rate_lut, there's no reason to start at index 0 which always contains the value 0. 0 is not a valid link rate.
This change should have no real effect but is a small cleanup.
Signed-off-by: Douglas Anderson dianders@chromium.org Tested-by: Rob Clark robdclark@gmail.com Reviewed-by: Rob Clark robdclark@gmail.com ---
Changes in v3: None Changes in v2: None
drivers/gpu/drm/bridge/ti-sn65dsi86.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c index 2fb9370a76e6..7b596af265e4 100644 --- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c +++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c @@ -458,7 +458,7 @@ static void ti_sn_bridge_set_dp_rate(struct ti_sn_bridge *pdata) /* set DP data rate */ dp_rate_mhz = ((bit_rate_mhz / pdata->dsi->lanes) * DP_CLK_FUDGE_NUM) / DP_CLK_FUDGE_DEN; - for (i = 0; i < ARRAY_SIZE(ti_sn_bridge_dp_rate_lut) - 1; i++) + for (i = 1; i < ARRAY_SIZE(ti_sn_bridge_dp_rate_lut) - 1; i++) if (ti_sn_bridge_dp_rate_lut[i] > dp_rate_mhz) break;
On Wed 18 Dec 14:35 PST 2019, Douglas Anderson wrote:
When we iterate over ti_sn_bridge_dp_rate_lut, there's no reason to start at index 0 which always contains the value 0. 0 is not a valid link rate.
This change should have no real effect but is a small cleanup.
Signed-off-by: Douglas Anderson dianders@chromium.org Tested-by: Rob Clark robdclark@gmail.com Reviewed-by: Rob Clark robdclark@gmail.com
Reviewed-by: Bjorn Andersson bjorn.andersson@linaro.org
Changes in v3: None Changes in v2: None
drivers/gpu/drm/bridge/ti-sn65dsi86.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c index 2fb9370a76e6..7b596af265e4 100644 --- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c +++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c @@ -458,7 +458,7 @@ static void ti_sn_bridge_set_dp_rate(struct ti_sn_bridge *pdata) /* set DP data rate */ dp_rate_mhz = ((bit_rate_mhz / pdata->dsi->lanes) * DP_CLK_FUDGE_NUM) / DP_CLK_FUDGE_DEN;
- for (i = 0; i < ARRAY_SIZE(ti_sn_bridge_dp_rate_lut) - 1; i++)
- for (i = 1; i < ARRAY_SIZE(ti_sn_bridge_dp_rate_lut) - 1; i++) if (ti_sn_bridge_dp_rate_lut[i] > dp_rate_mhz) break;
-- 2.24.1.735.g03f4e72817-goog
The ti-sn65dsi86 is a bridge from MIPI to DP and thus has two links: the MIPI link and the DP link. The two links do not need to have the same format or number of lanes. Stop using MIPI variables when talking about the DP link.
This has zero functional change because: * currently we are hardcoding the MIPI link as unpacked RGB888 which requires 24 bits and currently we are not changing the DP link rate from the bridge's default of 8 bits per pixel. * currently we are hardcoding both the MIPI and DP as being 4 lanes.
This is all in prep for fixing some of the above.
Signed-off-by: Douglas Anderson dianders@chromium.org Tested-by: Rob Clark robdclark@gmail.com Reviewed-by: Rob Clark robdclark@gmail.com ---
Changes in v3: None Changes in v2: None
drivers/gpu/drm/bridge/ti-sn65dsi86.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c index 7b596af265e4..ab644baaf90c 100644 --- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c +++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c @@ -100,6 +100,7 @@ struct ti_sn_bridge { struct drm_panel *panel; struct gpio_desc *enable_gpio; struct regulator_bulk_data supplies[SN_REGULATOR_SUPPLY_NUM]; + int dp_lanes; };
static const struct regmap_range ti_sn_bridge_volatile_ranges[] = { @@ -313,6 +314,7 @@ static int ti_sn_bridge_attach(struct drm_bridge *bridge) }
/* TODO: setting to 4 lanes always for now */ + pdata->dp_lanes = 4; dsi->lanes = 4; dsi->format = MIPI_DSI_FMT_RGB888; dsi->mode_flags = MIPI_DSI_MODE_VIDEO; @@ -451,13 +453,17 @@ static void ti_sn_bridge_set_dp_rate(struct ti_sn_bridge *pdata) struct drm_display_mode *mode = &pdata->bridge.encoder->crtc->state->adjusted_mode;
- /* set DSIA clk frequency */ - bit_rate_mhz = (mode->clock / 1000) * - mipi_dsi_pixel_format_to_bpp(pdata->dsi->format); + /* + * Calculate minimum bit rate based on our pixel clock. At + * the moment this driver never sets the DP_18BPP_EN bit in + * register 0x5b so we hardcode 24bpp. + */ + bit_rate_mhz = (mode->clock / 1000) * 24;
- /* set DP data rate */ - dp_rate_mhz = ((bit_rate_mhz / pdata->dsi->lanes) * DP_CLK_FUDGE_NUM) / + /* Calculate minimum DP data rate, taking 80% as per DP spec */ + dp_rate_mhz = ((bit_rate_mhz / pdata->dp_lanes) * DP_CLK_FUDGE_NUM) / DP_CLK_FUDGE_DEN; + for (i = 1; i < ARRAY_SIZE(ti_sn_bridge_dp_rate_lut) - 1; i++) if (ti_sn_bridge_dp_rate_lut[i] > dp_rate_mhz) break; @@ -517,7 +523,7 @@ static void ti_sn_bridge_enable(struct drm_bridge *bridge) CHA_DSI_LANES_MASK, val);
/* DP lane config */ - val = DP_NUM_LANES(pdata->dsi->lanes - 1); + val = DP_NUM_LANES(pdata->dp_lanes - 1); regmap_update_bits(pdata->regmap, SN_SSC_CONFIG_REG, DP_NUM_LANES_MASK, val);
On Wed 18 Dec 14:35 PST 2019, Douglas Anderson wrote:
The ti-sn65dsi86 is a bridge from MIPI to DP and thus has two links: the MIPI link and the DP link. The two links do not need to have the same format or number of lanes. Stop using MIPI variables when talking about the DP link.
This has zero functional change because:
- currently we are hardcoding the MIPI link as unpacked RGB888 which requires 24 bits and currently we are not changing the DP link rate from the bridge's default of 8 bits per pixel.
- currently we are hardcoding both the MIPI and DP as being 4 lanes.
This is all in prep for fixing some of the above.
Signed-off-by: Douglas Anderson dianders@chromium.org Tested-by: Rob Clark robdclark@gmail.com Reviewed-by: Rob Clark robdclark@gmail.com
Reviewed-by: Bjorn Andersson bjorn.andersson@linaro.org
Changes in v3: None Changes in v2: None
drivers/gpu/drm/bridge/ti-sn65dsi86.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c index 7b596af265e4..ab644baaf90c 100644 --- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c +++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c @@ -100,6 +100,7 @@ struct ti_sn_bridge { struct drm_panel *panel; struct gpio_desc *enable_gpio; struct regulator_bulk_data supplies[SN_REGULATOR_SUPPLY_NUM];
- int dp_lanes;
};
static const struct regmap_range ti_sn_bridge_volatile_ranges[] = { @@ -313,6 +314,7 @@ static int ti_sn_bridge_attach(struct drm_bridge *bridge) }
/* TODO: setting to 4 lanes always for now */
- pdata->dp_lanes = 4; dsi->lanes = 4; dsi->format = MIPI_DSI_FMT_RGB888; dsi->mode_flags = MIPI_DSI_MODE_VIDEO;
@@ -451,13 +453,17 @@ static void ti_sn_bridge_set_dp_rate(struct ti_sn_bridge *pdata) struct drm_display_mode *mode = &pdata->bridge.encoder->crtc->state->adjusted_mode;
- /* set DSIA clk frequency */
- bit_rate_mhz = (mode->clock / 1000) *
mipi_dsi_pixel_format_to_bpp(pdata->dsi->format);
- /*
* Calculate minimum bit rate based on our pixel clock. At* the moment this driver never sets the DP_18BPP_EN bit in* register 0x5b so we hardcode 24bpp.*/- bit_rate_mhz = (mode->clock / 1000) * 24;
- /* set DP data rate */
- dp_rate_mhz = ((bit_rate_mhz / pdata->dsi->lanes) * DP_CLK_FUDGE_NUM) /
- /* Calculate minimum DP data rate, taking 80% as per DP spec */
- dp_rate_mhz = ((bit_rate_mhz / pdata->dp_lanes) * DP_CLK_FUDGE_NUM) / DP_CLK_FUDGE_DEN;
- for (i = 1; i < ARRAY_SIZE(ti_sn_bridge_dp_rate_lut) - 1; i++) if (ti_sn_bridge_dp_rate_lut[i] > dp_rate_mhz) break;
@@ -517,7 +523,7 @@ static void ti_sn_bridge_enable(struct drm_bridge *bridge) CHA_DSI_LANES_MASK, val);
/* DP lane config */
- val = DP_NUM_LANES(pdata->dsi->lanes - 1);
- val = DP_NUM_LANES(pdata->dp_lanes - 1); regmap_update_bits(pdata->regmap, SN_SSC_CONFIG_REG, DP_NUM_LANES_MASK, val);
-- 2.24.1.735.g03f4e72817-goog
The driver used to say that the value to program into bridge register 0x93 was dp_lanes - 1. Looking at the datasheet for the bridge, this is wrong. The data sheet says: * 1 = 1 lane * 2 = 2 lanes * 3 = 4 lanes
A more proper way to express this encoding is min(dp_lanes, 3).
At the moment this change has zero effect because we've hardcoded the number of DP lanes to 4. ...and (4 - 1) == min(4, 3). How fortunate! ...but soon we'll stop hardcoding the number of lanes.
Signed-off-by: Douglas Anderson dianders@chromium.org Tested-by: Rob Clark robdclark@gmail.com Reviewed-by: Rob Clark robdclark@gmail.com ---
Changes in v3: None Changes in v2: None
drivers/gpu/drm/bridge/ti-sn65dsi86.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c index ab644baaf90c..d55d19759796 100644 --- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c +++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c @@ -523,7 +523,7 @@ static void ti_sn_bridge_enable(struct drm_bridge *bridge) CHA_DSI_LANES_MASK, val);
/* DP lane config */ - val = DP_NUM_LANES(pdata->dp_lanes - 1); + val = DP_NUM_LANES(min(pdata->dp_lanes, 3)); regmap_update_bits(pdata->regmap, SN_SSC_CONFIG_REG, DP_NUM_LANES_MASK, val);
On Wed 18 Dec 14:35 PST 2019, Douglas Anderson wrote:
The driver used to say that the value to program into bridge register 0x93 was dp_lanes - 1. Looking at the datasheet for the bridge, this is wrong. The data sheet says:
- 1 = 1 lane
- 2 = 2 lanes
- 3 = 4 lanes
A more proper way to express this encoding is min(dp_lanes, 3).
At the moment this change has zero effect because we've hardcoded the number of DP lanes to 4. ...and (4 - 1) == min(4, 3). How fortunate! ...but soon we'll stop hardcoding the number of lanes.
Signed-off-by: Douglas Anderson dianders@chromium.org Tested-by: Rob Clark robdclark@gmail.com Reviewed-by: Rob Clark robdclark@gmail.com
Reviewed-by: Bjorn Andersson bjorn.andersson@linaro.org
Changes in v3: None Changes in v2: None
drivers/gpu/drm/bridge/ti-sn65dsi86.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c index ab644baaf90c..d55d19759796 100644 --- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c +++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c @@ -523,7 +523,7 @@ static void ti_sn_bridge_enable(struct drm_bridge *bridge) CHA_DSI_LANES_MASK, val);
/* DP lane config */
- val = DP_NUM_LANES(pdata->dp_lanes - 1);
- val = DP_NUM_LANES(min(pdata->dp_lanes, 3)); regmap_update_bits(pdata->regmap, SN_SSC_CONFIG_REG, DP_NUM_LANES_MASK, val);
-- 2.24.1.735.g03f4e72817-goog
At least one panel hooked up to the bridge (AUO B116XAK01) only supports 1 lane of DP. Let's read this information and stop hardcoding 4 DP lanes.
Signed-off-by: Douglas Anderson dianders@chromium.org Tested-by: Rob Clark robdclark@gmail.com Reviewed-by: Rob Clark robdclark@gmail.com ---
Changes in v3: None Changes in v2: None
drivers/gpu/drm/bridge/ti-sn65dsi86.c | 32 +++++++++++++++++++++++++-- 1 file changed, 30 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c index d55d19759796..0fc9e97b2d98 100644 --- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c +++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c @@ -313,8 +313,7 @@ static int ti_sn_bridge_attach(struct drm_bridge *bridge) goto err_dsi_host; }
- /* TODO: setting to 4 lanes always for now */ - pdata->dp_lanes = 4; + /* TODO: setting to 4 MIPI lanes always for now */ dsi->lanes = 4; dsi->format = MIPI_DSI_FMT_RGB888; dsi->mode_flags = MIPI_DSI_MODE_VIDEO; @@ -511,12 +510,41 @@ static void ti_sn_bridge_set_video_timings(struct ti_sn_bridge *pdata) usleep_range(10000, 10500); /* 10ms delay recommended by spec */ }
+static unsigned int ti_sn_get_max_lanes(struct ti_sn_bridge *pdata) +{ + u8 data; + int ret; + + ret = drm_dp_dpcd_readb(&pdata->aux, DP_MAX_LANE_COUNT, &data); + if (ret != 1) { + DRM_DEV_ERROR(pdata->dev, + "Can't read lane count (%d); assuming 4\n", ret); + return 4; + } + + return data & DP_LANE_COUNT_MASK; +} + static void ti_sn_bridge_enable(struct drm_bridge *bridge) { struct ti_sn_bridge *pdata = bridge_to_ti_sn_bridge(bridge); unsigned int val; int ret;
+ /* + * Run with the maximum number of lanes that the DP sink supports. + * + * Depending use cases, we might want to revisit this later because: + * - It's plausible that someone may have run fewer lines to the + * sink than the sink actually supports, assuming that the lines + * will just be driven at a higher rate. + * - The DP spec seems to indicate that it's more important to minimize + * the number of lanes than the link rate. + * + * If we do revisit, it would be important to measure the power impact. + */ + pdata->dp_lanes = ti_sn_get_max_lanes(pdata); + /* DSI_A lane config */ val = CHA_DSI_LANES(4 - pdata->dsi->lanes); regmap_update_bits(pdata->regmap, SN_DSI_LANES_REG,
On Wed 18 Dec 14:35 PST 2019, Douglas Anderson wrote:
At least one panel hooked up to the bridge (AUO B116XAK01) only supports 1 lane of DP. Let's read this information and stop hardcoding 4 DP lanes.
Signed-off-by: Douglas Anderson dianders@chromium.org Tested-by: Rob Clark robdclark@gmail.com Reviewed-by: Rob Clark robdclark@gmail.com
Reviewed-by: Bjorn Andersson bjorn.andersson@linaro.org
Changes in v3: None Changes in v2: None
drivers/gpu/drm/bridge/ti-sn65dsi86.c | 32 +++++++++++++++++++++++++-- 1 file changed, 30 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c index d55d19759796..0fc9e97b2d98 100644 --- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c +++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c @@ -313,8 +313,7 @@ static int ti_sn_bridge_attach(struct drm_bridge *bridge) goto err_dsi_host; }
- /* TODO: setting to 4 lanes always for now */
- pdata->dp_lanes = 4;
- /* TODO: setting to 4 MIPI lanes always for now */ dsi->lanes = 4; dsi->format = MIPI_DSI_FMT_RGB888; dsi->mode_flags = MIPI_DSI_MODE_VIDEO;
@@ -511,12 +510,41 @@ static void ti_sn_bridge_set_video_timings(struct ti_sn_bridge *pdata) usleep_range(10000, 10500); /* 10ms delay recommended by spec */ }
+static unsigned int ti_sn_get_max_lanes(struct ti_sn_bridge *pdata) +{
- u8 data;
- int ret;
- ret = drm_dp_dpcd_readb(&pdata->aux, DP_MAX_LANE_COUNT, &data);
- if (ret != 1) {
DRM_DEV_ERROR(pdata->dev,"Can't read lane count (%d); assuming 4\n", ret);return 4;- }
- return data & DP_LANE_COUNT_MASK;
+}
static void ti_sn_bridge_enable(struct drm_bridge *bridge) { struct ti_sn_bridge *pdata = bridge_to_ti_sn_bridge(bridge); unsigned int val; int ret;
- /*
* Run with the maximum number of lanes that the DP sink supports.** Depending use cases, we might want to revisit this later because:* - It's plausible that someone may have run fewer lines to the* sink than the sink actually supports, assuming that the lines* will just be driven at a higher rate.* - The DP spec seems to indicate that it's more important to minimize* the number of lanes than the link rate.** If we do revisit, it would be important to measure the power impact.*/- pdata->dp_lanes = ti_sn_get_max_lanes(pdata);
- /* DSI_A lane config */ val = CHA_DSI_LANES(4 - pdata->dsi->lanes); regmap_update_bits(pdata->regmap, SN_DSI_LANES_REG,
-- 2.24.1.735.g03f4e72817-goog
The current bridge driver always forced us to use 24 bits per pixel over the DP link. This is a waste if you are hooked up to a panel that only supports 6 bits per color or fewer, since in that case you ran run at 18 bits per pixel and thus end up at a lower DP clock rate.
Let's support this.
While at it, let's clean up the math in the function to avoid rounding errors (and round in the correct direction when we have to round). Numbers are sufficiently small (because mode->clock is in kHz) that we don't need to worry about integer overflow.
Signed-off-by: Douglas Anderson dianders@chromium.org Tested-by: Rob Clark robdclark@gmail.com Reviewed-by: Rob Clark robdclark@gmail.com ---
Changes in v3: None Changes in v2: None
drivers/gpu/drm/bridge/ti-sn65dsi86.c | 27 ++++++++++++++++++--------- 1 file changed, 18 insertions(+), 9 deletions(-)
diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c index 0fc9e97b2d98..d5990a0947b9 100644 --- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c +++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c @@ -51,6 +51,7 @@ #define SN_ENH_FRAME_REG 0x5A #define VSTREAM_ENABLE BIT(3) #define SN_DATA_FORMAT_REG 0x5B +#define BPP_18_RGB BIT(0) #define SN_HPD_DISABLE_REG 0x5C #define HPD_DISABLE BIT(0) #define SN_AUX_WDATA_REG(x) (0x64 + (x)) @@ -436,6 +437,14 @@ static void ti_sn_bridge_set_dsi_rate(struct ti_sn_bridge *pdata) regmap_write(pdata->regmap, SN_DSIA_CLK_FREQ_REG, val); }
+static unsigned int ti_sn_bridge_get_bpp(struct ti_sn_bridge *pdata) +{ + if (pdata->connector.display_info.bpc <= 6) + return 18; + else + return 24; +} + /** * LUT index corresponds to register value and * LUT values corresponds to dp data rate supported @@ -447,21 +456,17 @@ static const unsigned int ti_sn_bridge_dp_rate_lut[] = {
static void ti_sn_bridge_set_dp_rate(struct ti_sn_bridge *pdata) { - unsigned int bit_rate_mhz, dp_rate_mhz; + unsigned int bit_rate_khz, dp_rate_mhz; unsigned int i; struct drm_display_mode *mode = &pdata->bridge.encoder->crtc->state->adjusted_mode;
- /* - * Calculate minimum bit rate based on our pixel clock. At - * the moment this driver never sets the DP_18BPP_EN bit in - * register 0x5b so we hardcode 24bpp. - */ - bit_rate_mhz = (mode->clock / 1000) * 24; + /* Calculate minimum bit rate based on our pixel clock. */ + bit_rate_khz = mode->clock * ti_sn_bridge_get_bpp(pdata);
/* Calculate minimum DP data rate, taking 80% as per DP spec */ - dp_rate_mhz = ((bit_rate_mhz / pdata->dp_lanes) * DP_CLK_FUDGE_NUM) / - DP_CLK_FUDGE_DEN; + dp_rate_mhz = DIV_ROUND_UP(bit_rate_khz * DP_CLK_FUDGE_NUM, + 1000 * pdata->dp_lanes * DP_CLK_FUDGE_DEN);
for (i = 1; i < ARRAY_SIZE(ti_sn_bridge_dp_rate_lut) - 1; i++) if (ti_sn_bridge_dp_rate_lut[i] > dp_rate_mhz) @@ -550,6 +555,10 @@ static void ti_sn_bridge_enable(struct drm_bridge *bridge) regmap_update_bits(pdata->regmap, SN_DSI_LANES_REG, CHA_DSI_LANES_MASK, val);
+ /* Set the DP output format (18 bpp or 24 bpp) */ + val = (ti_sn_bridge_get_bpp(pdata) == 18) ? BPP_18_RGB : 0; + regmap_update_bits(pdata->regmap, SN_DATA_FORMAT_REG, BPP_18_RGB, val); + /* DP lane config */ val = DP_NUM_LANES(min(pdata->dp_lanes, 3)); regmap_update_bits(pdata->regmap, SN_SSC_CONFIG_REG, DP_NUM_LANES_MASK,
On Wed 18 Dec 14:35 PST 2019, Douglas Anderson wrote:
The current bridge driver always forced us to use 24 bits per pixel over the DP link. This is a waste if you are hooked up to a panel that only supports 6 bits per color or fewer, since in that case you ran run at 18 bits per pixel and thus end up at a lower DP clock rate.
s/ran/can/
Let's support this.
While at it, let's clean up the math in the function to avoid rounding errors (and round in the correct direction when we have to round). Numbers are sufficiently small (because mode->clock is in kHz) that we don't need to worry about integer overflow.
Signed-off-by: Douglas Anderson dianders@chromium.org Tested-by: Rob Clark robdclark@gmail.com Reviewed-by: Rob Clark robdclark@gmail.com
Reviewed-by: Bjorn Andersson bjorn.andersson@linaro.org
Changes in v3: None Changes in v2: None
drivers/gpu/drm/bridge/ti-sn65dsi86.c | 27 ++++++++++++++++++--------- 1 file changed, 18 insertions(+), 9 deletions(-)
diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c index 0fc9e97b2d98..d5990a0947b9 100644 --- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c +++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c @@ -51,6 +51,7 @@ #define SN_ENH_FRAME_REG 0x5A #define VSTREAM_ENABLE BIT(3) #define SN_DATA_FORMAT_REG 0x5B +#define BPP_18_RGB BIT(0) #define SN_HPD_DISABLE_REG 0x5C #define HPD_DISABLE BIT(0) #define SN_AUX_WDATA_REG(x) (0x64 + (x)) @@ -436,6 +437,14 @@ static void ti_sn_bridge_set_dsi_rate(struct ti_sn_bridge *pdata) regmap_write(pdata->regmap, SN_DSIA_CLK_FREQ_REG, val); }
+static unsigned int ti_sn_bridge_get_bpp(struct ti_sn_bridge *pdata) +{
- if (pdata->connector.display_info.bpc <= 6)
return 18;- else
return 24;+}
/**
- LUT index corresponds to register value and
- LUT values corresponds to dp data rate supported
@@ -447,21 +456,17 @@ static const unsigned int ti_sn_bridge_dp_rate_lut[] = {
static void ti_sn_bridge_set_dp_rate(struct ti_sn_bridge *pdata) {
- unsigned int bit_rate_mhz, dp_rate_mhz;
- unsigned int bit_rate_khz, dp_rate_mhz; unsigned int i; struct drm_display_mode *mode = &pdata->bridge.encoder->crtc->state->adjusted_mode;
- /*
* Calculate minimum bit rate based on our pixel clock. At* the moment this driver never sets the DP_18BPP_EN bit in* register 0x5b so we hardcode 24bpp.*/- bit_rate_mhz = (mode->clock / 1000) * 24;
/* Calculate minimum bit rate based on our pixel clock. */
bit_rate_khz = mode->clock * ti_sn_bridge_get_bpp(pdata);
/* Calculate minimum DP data rate, taking 80% as per DP spec */
- dp_rate_mhz = ((bit_rate_mhz / pdata->dp_lanes) * DP_CLK_FUDGE_NUM) /
DP_CLK_FUDGE_DEN;
dp_rate_mhz = DIV_ROUND_UP(bit_rate_khz * DP_CLK_FUDGE_NUM,
1000 * pdata->dp_lanes * DP_CLK_FUDGE_DEN);for (i = 1; i < ARRAY_SIZE(ti_sn_bridge_dp_rate_lut) - 1; i++) if (ti_sn_bridge_dp_rate_lut[i] > dp_rate_mhz)
@@ -550,6 +555,10 @@ static void ti_sn_bridge_enable(struct drm_bridge *bridge) regmap_update_bits(pdata->regmap, SN_DSI_LANES_REG, CHA_DSI_LANES_MASK, val);
- /* Set the DP output format (18 bpp or 24 bpp) */
- val = (ti_sn_bridge_get_bpp(pdata) == 18) ? BPP_18_RGB : 0;
- regmap_update_bits(pdata->regmap, SN_DATA_FORMAT_REG, BPP_18_RGB, val);
- /* DP lane config */ val = DP_NUM_LANES(min(pdata->dp_lanes, 3)); regmap_update_bits(pdata->regmap, SN_SSC_CONFIG_REG, DP_NUM_LANES_MASK,
-- 2.24.1.735.g03f4e72817-goog
Andrzej / Neil,
On Mon, Feb 3, 2020 at 3:37 PM Bjorn Andersson bjorn.andersson@linaro.org wrote:
On Wed 18 Dec 14:35 PST 2019, Douglas Anderson wrote:
The current bridge driver always forced us to use 24 bits per pixel over the DP link. This is a waste if you are hooked up to a panel that only supports 6 bits per color or fewer, since in that case you ran run at 18 bits per pixel and thus end up at a lower DP clock rate.
s/ran/can/
I'm going to make the assumption that you can fix this typo when applying the patch and I'm not planning to send a v4. If that's not a good assumption then please yell.
Thanks!
-Doug
Andrzej / Neil,
On Mon, Feb 3, 2020 at 4:21 PM Doug Anderson dianders@chromium.org wrote:
Andrzej / Neil,
On Mon, Feb 3, 2020 at 3:37 PM Bjorn Andersson bjorn.andersson@linaro.org wrote:
On Wed 18 Dec 14:35 PST 2019, Douglas Anderson wrote:
The current bridge driver always forced us to use 24 bits per pixel over the DP link. This is a waste if you are hooked up to a panel that only supports 6 bits per color or fewer, since in that case you ran run at 18 bits per pixel and thus end up at a lower DP clock rate.
s/ran/can/
I'm going to make the assumption that you can fix this typo when applying the patch and I'm not planning to send a v4. If that's not a good assumption then please yell.
With -rc1 released, it seems like it might be a nice time to land this series. Do you happen to know if there is anything outstanding? Is one of you two the right person to land this series, or should I be asking someone else? I can see if I can find someone to take them through drm-misc if there's nobody else?
It's not massively crazy urgent or anything, but the patches have been floating for quite some time now and it'd be nice to know what the plan was. I also have another patch I'd like to post up but was hoping to get this series resolved first.
Thanks much!
-Doug
Hi,
On 13/02/2020 00:04, Doug Anderson wrote:
Andrzej / Neil,
On Mon, Feb 3, 2020 at 4:21 PM Doug Anderson dianders@chromium.org wrote:
Andrzej / Neil,
On Mon, Feb 3, 2020 at 3:37 PM Bjorn Andersson bjorn.andersson@linaro.org wrote:
On Wed 18 Dec 14:35 PST 2019, Douglas Anderson wrote:
The current bridge driver always forced us to use 24 bits per pixel over the DP link. This is a waste if you are hooked up to a panel that only supports 6 bits per color or fewer, since in that case you ran run at 18 bits per pixel and thus end up at a lower DP clock rate.
s/ran/can/
I'm going to make the assumption that you can fix this typo when applying the patch and I'm not planning to send a v4. If that's not a good assumption then please yell.
With -rc1 released, it seems like it might be a nice time to land this series. Do you happen to know if there is anything outstanding? Is one of you two the right person to land this series, or should I be asking someone else? I can see if I can find someone to take them through drm-misc if there's nobody else?
It's not massively crazy urgent or anything, but the patches have been floating for quite some time now and it'd be nice to know what the plan was. I also have another patch I'd like to post up but was hoping to get this series resolved first.
Thanks much!
-Doug
I will push it shortly, seems everything is fine and reviewed.
Neil
We'll re-organize the ti_sn_bridge_enable() function a bit to group together all the parts relating to link training and split them into a sub-function. This is not intended to have any functional change and is in preparation for trying link training several times at different rates. One small side effect here is that if link training fails we'll now leave the DP PLL disabled, but that seems like a sane thing to do.
Signed-off-by: Douglas Anderson dianders@chromium.org Tested-by: Rob Clark robdclark@gmail.com Reviewed-by: Rob Clark robdclark@gmail.com ---
Changes in v3: None Changes in v2: None
drivers/gpu/drm/bridge/ti-sn65dsi86.c | 86 ++++++++++++++++----------- 1 file changed, 52 insertions(+), 34 deletions(-)
diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c index d5990a0947b9..48fb4dc72e1c 100644 --- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c +++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c @@ -530,6 +530,46 @@ static unsigned int ti_sn_get_max_lanes(struct ti_sn_bridge *pdata) return data & DP_LANE_COUNT_MASK; }
+static int ti_sn_link_training(struct ti_sn_bridge *pdata) +{ + unsigned int val; + int ret; + + /* set dp clk frequency value */ + ti_sn_bridge_set_dp_rate(pdata); + + /* enable DP PLL */ + regmap_write(pdata->regmap, SN_PLL_ENABLE_REG, 1); + + ret = regmap_read_poll_timeout(pdata->regmap, SN_DPPLL_SRC_REG, val, + val & DPPLL_SRC_DP_PLL_LOCK, 1000, + 50 * 1000); + if (ret) { + DRM_ERROR("DP_PLL_LOCK polling failed (%d)\n", ret); + goto exit; + } + + /* Semi auto link training mode */ + regmap_write(pdata->regmap, SN_ML_TX_MODE_REG, 0x0A); + ret = regmap_read_poll_timeout(pdata->regmap, SN_ML_TX_MODE_REG, val, + val == ML_TX_MAIN_LINK_OFF || + val == ML_TX_NORMAL_MODE, 1000, + 500 * 1000); + if (ret) { + DRM_ERROR("Training complete polling failed (%d)\n", ret); + } else if (val == ML_TX_MAIN_LINK_OFF) { + DRM_ERROR("Link training failed, link is off\n"); + ret = -EIO; + } + +exit: + /* Disable the PLL if we failed */ + if (ret) + regmap_write(pdata->regmap, SN_PLL_ENABLE_REG, 0); + + return ret; +} + static void ti_sn_bridge_enable(struct drm_bridge *bridge) { struct ti_sn_bridge *pdata = bridge_to_ti_sn_bridge(bridge); @@ -555,29 +595,8 @@ static void ti_sn_bridge_enable(struct drm_bridge *bridge) regmap_update_bits(pdata->regmap, SN_DSI_LANES_REG, CHA_DSI_LANES_MASK, val);
- /* Set the DP output format (18 bpp or 24 bpp) */ - val = (ti_sn_bridge_get_bpp(pdata) == 18) ? BPP_18_RGB : 0; - regmap_update_bits(pdata->regmap, SN_DATA_FORMAT_REG, BPP_18_RGB, val); - - /* DP lane config */ - val = DP_NUM_LANES(min(pdata->dp_lanes, 3)); - regmap_update_bits(pdata->regmap, SN_SSC_CONFIG_REG, DP_NUM_LANES_MASK, - val); - - /* set dsi/dp clk frequency value */ + /* set dsi clk frequency value */ ti_sn_bridge_set_dsi_rate(pdata); - ti_sn_bridge_set_dp_rate(pdata); - - /* enable DP PLL */ - regmap_write(pdata->regmap, SN_PLL_ENABLE_REG, 1); - - ret = regmap_read_poll_timeout(pdata->regmap, SN_DPPLL_SRC_REG, val, - val & DPPLL_SRC_DP_PLL_LOCK, 1000, - 50 * 1000); - if (ret) { - DRM_ERROR("DP_PLL_LOCK polling failed (%d)\n", ret); - return; - }
/** * The SN65DSI86 only supports ASSR Display Authentication method and @@ -588,19 +607,18 @@ static void ti_sn_bridge_enable(struct drm_bridge *bridge) drm_dp_dpcd_writeb(&pdata->aux, DP_EDP_CONFIGURATION_SET, DP_ALTERNATE_SCRAMBLER_RESET_ENABLE);
- /* Semi auto link training mode */ - regmap_write(pdata->regmap, SN_ML_TX_MODE_REG, 0x0A); - ret = regmap_read_poll_timeout(pdata->regmap, SN_ML_TX_MODE_REG, val, - val == ML_TX_MAIN_LINK_OFF || - val == ML_TX_NORMAL_MODE, 1000, - 500 * 1000); - if (ret) { - DRM_ERROR("Training complete polling failed (%d)\n", ret); - return; - } else if (val == ML_TX_MAIN_LINK_OFF) { - DRM_ERROR("Link training failed, link is off\n"); + /* Set the DP output format (18 bpp or 24 bpp) */ + val = (ti_sn_bridge_get_bpp(pdata) == 18) ? BPP_18_RGB : 0; + regmap_update_bits(pdata->regmap, SN_DATA_FORMAT_REG, BPP_18_RGB, val); + + /* DP lane config */ + val = DP_NUM_LANES(min(pdata->dp_lanes, 3)); + regmap_update_bits(pdata->regmap, SN_SSC_CONFIG_REG, DP_NUM_LANES_MASK, + val); + + ret = ti_sn_link_training(pdata); + if (ret) return; - }
/* config video parameters */ ti_sn_bridge_set_video_timings(pdata);
On Wed 18 Dec 14:35 PST 2019, Douglas Anderson wrote:
We'll re-organize the ti_sn_bridge_enable() function a bit to group together all the parts relating to link training and split them into a sub-function. This is not intended to have any functional change and is in preparation for trying link training several times at different rates. One small side effect here is that if link training fails we'll now leave the DP PLL disabled, but that seems like a sane thing to do.
Signed-off-by: Douglas Anderson dianders@chromium.org Tested-by: Rob Clark robdclark@gmail.com Reviewed-by: Rob Clark robdclark@gmail.com
Reviewed-by: Bjorn Andersson bjorn.andersson@linaro.org
Changes in v3: None Changes in v2: None
drivers/gpu/drm/bridge/ti-sn65dsi86.c | 86 ++++++++++++++++----------- 1 file changed, 52 insertions(+), 34 deletions(-)
diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c index d5990a0947b9..48fb4dc72e1c 100644 --- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c +++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c @@ -530,6 +530,46 @@ static unsigned int ti_sn_get_max_lanes(struct ti_sn_bridge *pdata) return data & DP_LANE_COUNT_MASK; }
+static int ti_sn_link_training(struct ti_sn_bridge *pdata) +{
- unsigned int val;
- int ret;
- /* set dp clk frequency value */
- ti_sn_bridge_set_dp_rate(pdata);
- /* enable DP PLL */
- regmap_write(pdata->regmap, SN_PLL_ENABLE_REG, 1);
- ret = regmap_read_poll_timeout(pdata->regmap, SN_DPPLL_SRC_REG, val,
val & DPPLL_SRC_DP_PLL_LOCK, 1000,50 * 1000);- if (ret) {
DRM_ERROR("DP_PLL_LOCK polling failed (%d)\n", ret);goto exit;- }
- /* Semi auto link training mode */
- regmap_write(pdata->regmap, SN_ML_TX_MODE_REG, 0x0A);
- ret = regmap_read_poll_timeout(pdata->regmap, SN_ML_TX_MODE_REG, val,
val == ML_TX_MAIN_LINK_OFF ||val == ML_TX_NORMAL_MODE, 1000,500 * 1000);- if (ret) {
DRM_ERROR("Training complete polling failed (%d)\n", ret);- } else if (val == ML_TX_MAIN_LINK_OFF) {
DRM_ERROR("Link training failed, link is off\n");ret = -EIO;- }
+exit:
- /* Disable the PLL if we failed */
- if (ret)
regmap_write(pdata->regmap, SN_PLL_ENABLE_REG, 0);- return ret;
+}
static void ti_sn_bridge_enable(struct drm_bridge *bridge) { struct ti_sn_bridge *pdata = bridge_to_ti_sn_bridge(bridge); @@ -555,29 +595,8 @@ static void ti_sn_bridge_enable(struct drm_bridge *bridge) regmap_update_bits(pdata->regmap, SN_DSI_LANES_REG, CHA_DSI_LANES_MASK, val);
- /* Set the DP output format (18 bpp or 24 bpp) */
- val = (ti_sn_bridge_get_bpp(pdata) == 18) ? BPP_18_RGB : 0;
- regmap_update_bits(pdata->regmap, SN_DATA_FORMAT_REG, BPP_18_RGB, val);
- /* DP lane config */
- val = DP_NUM_LANES(min(pdata->dp_lanes, 3));
- regmap_update_bits(pdata->regmap, SN_SSC_CONFIG_REG, DP_NUM_LANES_MASK,
val);- /* set dsi/dp clk frequency value */
- /* set dsi clk frequency value */ ti_sn_bridge_set_dsi_rate(pdata);
ti_sn_bridge_set_dp_rate(pdata);
/* enable DP PLL */
regmap_write(pdata->regmap, SN_PLL_ENABLE_REG, 1);
ret = regmap_read_poll_timeout(pdata->regmap, SN_DPPLL_SRC_REG, val,
val & DPPLL_SRC_DP_PLL_LOCK, 1000,50 * 1000);if (ret) {
DRM_ERROR("DP_PLL_LOCK polling failed (%d)\n", ret);return;}
/**
- The SN65DSI86 only supports ASSR Display Authentication method and
@@ -588,19 +607,18 @@ static void ti_sn_bridge_enable(struct drm_bridge *bridge) drm_dp_dpcd_writeb(&pdata->aux, DP_EDP_CONFIGURATION_SET, DP_ALTERNATE_SCRAMBLER_RESET_ENABLE);
- /* Semi auto link training mode */
- regmap_write(pdata->regmap, SN_ML_TX_MODE_REG, 0x0A);
- ret = regmap_read_poll_timeout(pdata->regmap, SN_ML_TX_MODE_REG, val,
val == ML_TX_MAIN_LINK_OFF ||val == ML_TX_NORMAL_MODE, 1000,500 * 1000);- if (ret) {
DRM_ERROR("Training complete polling failed (%d)\n", ret);return;- } else if (val == ML_TX_MAIN_LINK_OFF) {
DRM_ERROR("Link training failed, link is off\n");
- /* Set the DP output format (18 bpp or 24 bpp) */
- val = (ti_sn_bridge_get_bpp(pdata) == 18) ? BPP_18_RGB : 0;
- regmap_update_bits(pdata->regmap, SN_DATA_FORMAT_REG, BPP_18_RGB, val);
- /* DP lane config */
- val = DP_NUM_LANES(min(pdata->dp_lanes, 3));
- regmap_update_bits(pdata->regmap, SN_SSC_CONFIG_REG, DP_NUM_LANES_MASK,
val);- ret = ti_sn_link_training(pdata);
- if (ret) return;
}
/* config video parameters */ ti_sn_bridge_set_video_timings(pdata);
-- 2.24.1.735.g03f4e72817-goog
If we fail training at a lower DP link rate let's now keep trying until we run out of rates to try. Basically the algorithm here is to start at the link rate that is the theoretical minimum and then slowly bump up until we run out of rates or hit the max rate of the sink. We query the sink using a DPCD read.
This is, in fact, important in practice. Specifically at least one panel hooked up to the bridge (AUO B116XAK01) had a theoretical min rate more than 1.62 GHz (if run at 24 bpp) and fails to train at the next rate (2.16 GHz). It would train at 2.7 GHz, though.
Signed-off-by: Douglas Anderson dianders@chromium.org Tested-by: Rob Clark robdclark@gmail.com Reviewed-by: Rob Clark robdclark@gmail.com ---
Changes in v3: None Changes in v2: - Squash in maybe-uninitialized fix from Rob Clark.
drivers/gpu/drm/bridge/ti-sn65dsi86.c | 71 ++++++++++++++++++++++----- 1 file changed, 60 insertions(+), 11 deletions(-)
diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c index 48fb4dc72e1c..e1b817ccd9c7 100644 --- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c +++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c @@ -454,7 +454,7 @@ static const unsigned int ti_sn_bridge_dp_rate_lut[] = { 0, 1620, 2160, 2430, 2700, 3240, 4320, 5400 };
-static void ti_sn_bridge_set_dp_rate(struct ti_sn_bridge *pdata) +static int ti_sn_bridge_calc_min_dp_rate_idx(struct ti_sn_bridge *pdata) { unsigned int bit_rate_khz, dp_rate_mhz; unsigned int i; @@ -472,8 +472,42 @@ static void ti_sn_bridge_set_dp_rate(struct ti_sn_bridge *pdata) if (ti_sn_bridge_dp_rate_lut[i] > dp_rate_mhz) break;
- regmap_update_bits(pdata->regmap, SN_DATARATE_CONFIG_REG, - DP_DATARATE_MASK, DP_DATARATE(i)); + return i; +} + +static int ti_sn_bridge_get_max_dp_rate_idx(struct ti_sn_bridge *pdata) +{ + u8 data; + int ret; + + ret = drm_dp_dpcd_readb(&pdata->aux, DP_MAX_LINK_RATE, &data); + if (ret != 1) { + DRM_DEV_ERROR(pdata->dev, + "Can't read max rate (%d); assuming 5.4 GHz\n", + ret); + return ARRAY_SIZE(ti_sn_bridge_dp_rate_lut) - 1; + } + + /* + * Return an index into ti_sn_bridge_dp_rate_lut. Just hardcode + * these indicies since it's not like the register spec is ever going + * to change and a loop would just be more complicated. Apparently + * the DP sink can only return these few rates as supported even + * though the bridge allows some rates in between. + */ + switch (data) { + case DP_LINK_BW_1_62: + return 1; + case DP_LINK_BW_2_7: + return 4; + case DP_LINK_BW_5_4: + return 7; + } + + DRM_DEV_ERROR(pdata->dev, + "Unexpected max data rate (%#x); assuming 5.4 GHz\n", + (int)data); + return ARRAY_SIZE(ti_sn_bridge_dp_rate_lut) - 1; }
static void ti_sn_bridge_set_video_timings(struct ti_sn_bridge *pdata) @@ -530,13 +564,15 @@ static unsigned int ti_sn_get_max_lanes(struct ti_sn_bridge *pdata) return data & DP_LANE_COUNT_MASK; }
-static int ti_sn_link_training(struct ti_sn_bridge *pdata) +static int ti_sn_link_training(struct ti_sn_bridge *pdata, int dp_rate_idx, + const char **last_err_str) { unsigned int val; int ret;
/* set dp clk frequency value */ - ti_sn_bridge_set_dp_rate(pdata); + regmap_update_bits(pdata->regmap, SN_DATARATE_CONFIG_REG, + DP_DATARATE_MASK, DP_DATARATE(dp_rate_idx));
/* enable DP PLL */ regmap_write(pdata->regmap, SN_PLL_ENABLE_REG, 1); @@ -545,7 +581,7 @@ static int ti_sn_link_training(struct ti_sn_bridge *pdata) val & DPPLL_SRC_DP_PLL_LOCK, 1000, 50 * 1000); if (ret) { - DRM_ERROR("DP_PLL_LOCK polling failed (%d)\n", ret); + *last_err_str = "DP_PLL_LOCK polling failed"; goto exit; }
@@ -556,9 +592,9 @@ static int ti_sn_link_training(struct ti_sn_bridge *pdata) val == ML_TX_NORMAL_MODE, 1000, 500 * 1000); if (ret) { - DRM_ERROR("Training complete polling failed (%d)\n", ret); + *last_err_str = "Training complete polling failed"; } else if (val == ML_TX_MAIN_LINK_OFF) { - DRM_ERROR("Link training failed, link is off\n"); + *last_err_str = "Link training failed, link is off"; ret = -EIO; }
@@ -573,8 +609,11 @@ static int ti_sn_link_training(struct ti_sn_bridge *pdata) static void ti_sn_bridge_enable(struct drm_bridge *bridge) { struct ti_sn_bridge *pdata = bridge_to_ti_sn_bridge(bridge); + const char *last_err_str = "No supported DP rate"; + int dp_rate_idx; + int max_dp_rate_idx; unsigned int val; - int ret; + int ret = -EINVAL;
/* * Run with the maximum number of lanes that the DP sink supports. @@ -616,9 +655,19 @@ static void ti_sn_bridge_enable(struct drm_bridge *bridge) regmap_update_bits(pdata->regmap, SN_SSC_CONFIG_REG, DP_NUM_LANES_MASK, val);
- ret = ti_sn_link_training(pdata); - if (ret) + /* Train until we run out of rates */ + max_dp_rate_idx = ti_sn_bridge_get_max_dp_rate_idx(pdata); + for (dp_rate_idx = ti_sn_bridge_calc_min_dp_rate_idx(pdata); + dp_rate_idx <= max_dp_rate_idx; + dp_rate_idx++) { + ret = ti_sn_link_training(pdata, dp_rate_idx, &last_err_str); + if (!ret) + break; + } + if (ret) { + DRM_DEV_ERROR(pdata->dev, "%s (%d)\n", last_err_str, ret); return; + }
/* config video parameters */ ti_sn_bridge_set_video_timings(pdata);
On Wed 18 Dec 14:35 PST 2019, Douglas Anderson wrote:
If we fail training at a lower DP link rate let's now keep trying until we run out of rates to try. Basically the algorithm here is to start at the link rate that is the theoretical minimum and then slowly bump up until we run out of rates or hit the max rate of the sink. We query the sink using a DPCD read.
This is, in fact, important in practice. Specifically at least one panel hooked up to the bridge (AUO B116XAK01) had a theoretical min rate more than 1.62 GHz (if run at 24 bpp) and fails to train at the next rate (2.16 GHz). It would train at 2.7 GHz, though.
Signed-off-by: Douglas Anderson dianders@chromium.org Tested-by: Rob Clark robdclark@gmail.com Reviewed-by: Rob Clark robdclark@gmail.com
Reviewed-by: Bjorn Andersson bjorn.andersson@linaro.org
Changes in v3: None Changes in v2:
- Squash in maybe-uninitialized fix from Rob Clark.
drivers/gpu/drm/bridge/ti-sn65dsi86.c | 71 ++++++++++++++++++++++----- 1 file changed, 60 insertions(+), 11 deletions(-)
diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c index 48fb4dc72e1c..e1b817ccd9c7 100644 --- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c +++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c @@ -454,7 +454,7 @@ static const unsigned int ti_sn_bridge_dp_rate_lut[] = { 0, 1620, 2160, 2430, 2700, 3240, 4320, 5400 };
-static void ti_sn_bridge_set_dp_rate(struct ti_sn_bridge *pdata) +static int ti_sn_bridge_calc_min_dp_rate_idx(struct ti_sn_bridge *pdata) { unsigned int bit_rate_khz, dp_rate_mhz; unsigned int i; @@ -472,8 +472,42 @@ static void ti_sn_bridge_set_dp_rate(struct ti_sn_bridge *pdata) if (ti_sn_bridge_dp_rate_lut[i] > dp_rate_mhz) break;
- regmap_update_bits(pdata->regmap, SN_DATARATE_CONFIG_REG,
DP_DATARATE_MASK, DP_DATARATE(i));
- return i;
+}
+static int ti_sn_bridge_get_max_dp_rate_idx(struct ti_sn_bridge *pdata) +{
- u8 data;
- int ret;
- ret = drm_dp_dpcd_readb(&pdata->aux, DP_MAX_LINK_RATE, &data);
- if (ret != 1) {
DRM_DEV_ERROR(pdata->dev,"Can't read max rate (%d); assuming 5.4 GHz\n",ret);return ARRAY_SIZE(ti_sn_bridge_dp_rate_lut) - 1;- }
- /*
* Return an index into ti_sn_bridge_dp_rate_lut. Just hardcode* these indicies since it's not like the register spec is ever going* to change and a loop would just be more complicated. Apparently* the DP sink can only return these few rates as supported even* though the bridge allows some rates in between.*/- switch (data) {
- case DP_LINK_BW_1_62:
return 1;- case DP_LINK_BW_2_7:
return 4;- case DP_LINK_BW_5_4:
return 7;- }
- DRM_DEV_ERROR(pdata->dev,
"Unexpected max data rate (%#x); assuming 5.4 GHz\n",(int)data);- return ARRAY_SIZE(ti_sn_bridge_dp_rate_lut) - 1;
}
static void ti_sn_bridge_set_video_timings(struct ti_sn_bridge *pdata) @@ -530,13 +564,15 @@ static unsigned int ti_sn_get_max_lanes(struct ti_sn_bridge *pdata) return data & DP_LANE_COUNT_MASK; }
-static int ti_sn_link_training(struct ti_sn_bridge *pdata) +static int ti_sn_link_training(struct ti_sn_bridge *pdata, int dp_rate_idx,
const char **last_err_str){ unsigned int val; int ret;
/* set dp clk frequency value */
- ti_sn_bridge_set_dp_rate(pdata);
regmap_update_bits(pdata->regmap, SN_DATARATE_CONFIG_REG,
DP_DATARATE_MASK, DP_DATARATE(dp_rate_idx));/* enable DP PLL */ regmap_write(pdata->regmap, SN_PLL_ENABLE_REG, 1);
@@ -545,7 +581,7 @@ static int ti_sn_link_training(struct ti_sn_bridge *pdata) val & DPPLL_SRC_DP_PLL_LOCK, 1000, 50 * 1000); if (ret) {
DRM_ERROR("DP_PLL_LOCK polling failed (%d)\n", ret);
*last_err_str = "DP_PLL_LOCK polling failed";@@ -556,9 +592,9 @@ static int ti_sn_link_training(struct ti_sn_bridge *pdata) val == ML_TX_NORMAL_MODE, 1000, 500 * 1000); if (ret) {
DRM_ERROR("Training complete polling failed (%d)\n", ret);
*last_err_str = "Training complete polling failed";
DRM_ERROR("Link training failed, link is off\n");
*last_err_str = "Link training failed, link is off";@@ -573,8 +609,11 @@ static int ti_sn_link_training(struct ti_sn_bridge *pdata) static void ti_sn_bridge_enable(struct drm_bridge *bridge) { struct ti_sn_bridge *pdata = bridge_to_ti_sn_bridge(bridge);
- const char *last_err_str = "No supported DP rate";
- int dp_rate_idx;
- int max_dp_rate_idx; unsigned int val;
- int ret;
int ret = -EINVAL;
/*
- Run with the maximum number of lanes that the DP sink supports.
@@ -616,9 +655,19 @@ static void ti_sn_bridge_enable(struct drm_bridge *bridge) regmap_update_bits(pdata->regmap, SN_SSC_CONFIG_REG, DP_NUM_LANES_MASK, val);
- ret = ti_sn_link_training(pdata);
- if (ret)
/* Train until we run out of rates */
max_dp_rate_idx = ti_sn_bridge_get_max_dp_rate_idx(pdata);
for (dp_rate_idx = ti_sn_bridge_calc_min_dp_rate_idx(pdata);
dp_rate_idx <= max_dp_rate_idx;dp_rate_idx++) {ret = ti_sn_link_training(pdata, dp_rate_idx, &last_err_str);if (!ret)break;}
if (ret) {
DRM_DEV_ERROR(pdata->dev, "%s (%d)\n", last_err_str, ret);return;
}
/* config video parameters */ ti_sn_bridge_set_video_timings(pdata);
-- 2.24.1.735.g03f4e72817-goog
Based on work by Bjorn Andersson bjorn.andersson@linaro.org, Jeffrey Hugo jeffrey.l.hugo@gmail.com, and Rob Clark robdclark@chromium.org.
Let's read the SUPPORTED_LINK_RATES and/or MAX_LINK_RATE (depending on the eDP version of the sink) to figure out what eDP rates are supported and pick the ideal one.
NOTE: I have only personally tested this code on eDP panels that are 1.3 or older. Code reading SUPPORTED_LINK_RATES for DP 1.4+ was tested by hacking the code to pretend that a table was there.
Signed-off-by: Douglas Anderson dianders@chromium.org ---
Changes in v3: - Init rate_valid table, don't rely on stack being 0 (oops). - Rename rate_times_200khz to rate_per_200khz. - Loop over the ti_sn_bridge_dp_rate_lut table, making code smaller. - Use 'true' instead of 1 for bools. - Added note to commit message noting DP 1.4+ isn't well tested.
Changes in v2: - Patch ("Avoid invalid rates") replaces ("Skip non-standard DP rates")
drivers/gpu/drm/bridge/ti-sn65dsi86.c | 100 +++++++++++++++++++------- 1 file changed, 75 insertions(+), 25 deletions(-)
diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c index e1b817ccd9c7..a57c6108cb1f 100644 --- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c +++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c @@ -475,39 +475,85 @@ static int ti_sn_bridge_calc_min_dp_rate_idx(struct ti_sn_bridge *pdata) return i; }
-static int ti_sn_bridge_get_max_dp_rate_idx(struct ti_sn_bridge *pdata) +static void ti_sn_bridge_read_valid_rates(struct ti_sn_bridge *pdata, + bool rate_valid[]) { - u8 data; + unsigned int rate_per_200khz; + unsigned int rate_mhz; + u8 dpcd_val; int ret; + int i, j; + + ret = drm_dp_dpcd_readb(&pdata->aux, DP_EDP_DPCD_REV, &dpcd_val); + if (ret != 1) { + DRM_DEV_ERROR(pdata->dev, + "Can't read eDP rev (%d), assuming 1.1\n", ret); + dpcd_val = DP_EDP_11; + } + + if (dpcd_val >= DP_EDP_14) { + /* eDP 1.4 devices must provide a custom table */ + __le16 sink_rates[DP_MAX_SUPPORTED_RATES]; + + ret = drm_dp_dpcd_read(&pdata->aux, DP_SUPPORTED_LINK_RATES, + sink_rates, sizeof(sink_rates)); + + if (ret != sizeof(sink_rates)) { + DRM_DEV_ERROR(pdata->dev, + "Can't read supported rate table (%d)\n", ret); + + /* By zeroing we'll fall back to DP_MAX_LINK_RATE. */ + memset(sink_rates, 0, sizeof(sink_rates)); + } + + for (i = 0; i < ARRAY_SIZE(sink_rates); i++) { + rate_per_200khz = le16_to_cpu(sink_rates[i]); + + if (!rate_per_200khz) + break; + + rate_mhz = rate_per_200khz * 200 / 1000; + for (j = 0; + j < ARRAY_SIZE(ti_sn_bridge_dp_rate_lut); + j++) { + if (ti_sn_bridge_dp_rate_lut[j] == rate_mhz) + rate_valid[j] = true; + } + } + + for (i = 0; i < ARRAY_SIZE(ti_sn_bridge_dp_rate_lut); i++) { + if (rate_valid[i]) + return; + } + DRM_DEV_ERROR(pdata->dev, + "No matching eDP rates in table; falling back\n"); + }
- ret = drm_dp_dpcd_readb(&pdata->aux, DP_MAX_LINK_RATE, &data); + /* On older versions best we can do is use DP_MAX_LINK_RATE */ + ret = drm_dp_dpcd_readb(&pdata->aux, DP_MAX_LINK_RATE, &dpcd_val); if (ret != 1) { DRM_DEV_ERROR(pdata->dev, "Can't read max rate (%d); assuming 5.4 GHz\n", ret); - return ARRAY_SIZE(ti_sn_bridge_dp_rate_lut) - 1; + dpcd_val = DP_LINK_BW_5_4; }
- /* - * Return an index into ti_sn_bridge_dp_rate_lut. Just hardcode - * these indicies since it's not like the register spec is ever going - * to change and a loop would just be more complicated. Apparently - * the DP sink can only return these few rates as supported even - * though the bridge allows some rates in between. - */ - switch (data) { - case DP_LINK_BW_1_62: - return 1; - case DP_LINK_BW_2_7: - return 4; + switch (dpcd_val) { + default: + DRM_DEV_ERROR(pdata->dev, + "Unexpected max rate (%#x); assuming 5.4 GHz\n", + (int)dpcd_val); + /* fall through */ case DP_LINK_BW_5_4: - return 7; + rate_valid[7] = 1; + /* fall through */ + case DP_LINK_BW_2_7: + rate_valid[4] = 1; + /* fall through */ + case DP_LINK_BW_1_62: + rate_valid[1] = 1; + break; } - - DRM_DEV_ERROR(pdata->dev, - "Unexpected max data rate (%#x); assuming 5.4 GHz\n", - (int)data); - return ARRAY_SIZE(ti_sn_bridge_dp_rate_lut) - 1; }
static void ti_sn_bridge_set_video_timings(struct ti_sn_bridge *pdata) @@ -609,9 +655,9 @@ static int ti_sn_link_training(struct ti_sn_bridge *pdata, int dp_rate_idx, static void ti_sn_bridge_enable(struct drm_bridge *bridge) { struct ti_sn_bridge *pdata = bridge_to_ti_sn_bridge(bridge); + bool rate_valid[ARRAY_SIZE(ti_sn_bridge_dp_rate_lut)] = { }; const char *last_err_str = "No supported DP rate"; int dp_rate_idx; - int max_dp_rate_idx; unsigned int val; int ret = -EINVAL;
@@ -655,11 +701,15 @@ static void ti_sn_bridge_enable(struct drm_bridge *bridge) regmap_update_bits(pdata->regmap, SN_SSC_CONFIG_REG, DP_NUM_LANES_MASK, val);
+ ti_sn_bridge_read_valid_rates(pdata, rate_valid); + /* Train until we run out of rates */ - max_dp_rate_idx = ti_sn_bridge_get_max_dp_rate_idx(pdata); for (dp_rate_idx = ti_sn_bridge_calc_min_dp_rate_idx(pdata); - dp_rate_idx <= max_dp_rate_idx; + dp_rate_idx < ARRAY_SIZE(ti_sn_bridge_dp_rate_lut); dp_rate_idx++) { + if (!rate_valid[dp_rate_idx]) + continue; + ret = ti_sn_link_training(pdata, dp_rate_idx, &last_err_str); if (!ret) break;
On Wed 18 Dec 14:35 PST 2019, Douglas Anderson wrote:
Based on work by Bjorn Andersson bjorn.andersson@linaro.org, Jeffrey Hugo jeffrey.l.hugo@gmail.com, and Rob Clark robdclark@chromium.org.
Let's read the SUPPORTED_LINK_RATES and/or MAX_LINK_RATE (depending on the eDP version of the sink) to figure out what eDP rates are supported and pick the ideal one.
NOTE: I have only personally tested this code on eDP panels that are 1.3 or older. Code reading SUPPORTED_LINK_RATES for DP 1.4+ was tested by hacking the code to pretend that a table was there.
Signed-off-by: Douglas Anderson dianders@chromium.org
Reviewed-by: Bjorn Andersson bjorn.andersson@linaro.org
Changes in v3:
- Init rate_valid table, don't rely on stack being 0 (oops).
- Rename rate_times_200khz to rate_per_200khz.
- Loop over the ti_sn_bridge_dp_rate_lut table, making code smaller.
- Use 'true' instead of 1 for bools.
- Added note to commit message noting DP 1.4+ isn't well tested.
Changes in v2:
- Patch ("Avoid invalid rates") replaces ("Skip non-standard DP rates")
drivers/gpu/drm/bridge/ti-sn65dsi86.c | 100 +++++++++++++++++++------- 1 file changed, 75 insertions(+), 25 deletions(-)
diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c index e1b817ccd9c7..a57c6108cb1f 100644 --- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c +++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c @@ -475,39 +475,85 @@ static int ti_sn_bridge_calc_min_dp_rate_idx(struct ti_sn_bridge *pdata) return i; }
-static int ti_sn_bridge_get_max_dp_rate_idx(struct ti_sn_bridge *pdata) +static void ti_sn_bridge_read_valid_rates(struct ti_sn_bridge *pdata,
bool rate_valid[]){
- u8 data;
- unsigned int rate_per_200khz;
- unsigned int rate_mhz;
- u8 dpcd_val; int ret;
- int i, j;
- ret = drm_dp_dpcd_readb(&pdata->aux, DP_EDP_DPCD_REV, &dpcd_val);
- if (ret != 1) {
DRM_DEV_ERROR(pdata->dev,"Can't read eDP rev (%d), assuming 1.1\n", ret);dpcd_val = DP_EDP_11;- }
- if (dpcd_val >= DP_EDP_14) {
/* eDP 1.4 devices must provide a custom table */__le16 sink_rates[DP_MAX_SUPPORTED_RATES];ret = drm_dp_dpcd_read(&pdata->aux, DP_SUPPORTED_LINK_RATES,sink_rates, sizeof(sink_rates));if (ret != sizeof(sink_rates)) {DRM_DEV_ERROR(pdata->dev,"Can't read supported rate table (%d)\n", ret);/* By zeroing we'll fall back to DP_MAX_LINK_RATE. */memset(sink_rates, 0, sizeof(sink_rates));}for (i = 0; i < ARRAY_SIZE(sink_rates); i++) {rate_per_200khz = le16_to_cpu(sink_rates[i]);if (!rate_per_200khz)break;rate_mhz = rate_per_200khz * 200 / 1000;for (j = 0;j < ARRAY_SIZE(ti_sn_bridge_dp_rate_lut);j++) {if (ti_sn_bridge_dp_rate_lut[j] == rate_mhz)rate_valid[j] = true;}}for (i = 0; i < ARRAY_SIZE(ti_sn_bridge_dp_rate_lut); i++) {if (rate_valid[i])return;}DRM_DEV_ERROR(pdata->dev,"No matching eDP rates in table; falling back\n");- }
- ret = drm_dp_dpcd_readb(&pdata->aux, DP_MAX_LINK_RATE, &data);
- /* On older versions best we can do is use DP_MAX_LINK_RATE */
- ret = drm_dp_dpcd_readb(&pdata->aux, DP_MAX_LINK_RATE, &dpcd_val); if (ret != 1) { DRM_DEV_ERROR(pdata->dev, "Can't read max rate (%d); assuming 5.4 GHz\n", ret);
return ARRAY_SIZE(ti_sn_bridge_dp_rate_lut) - 1;
dpcd_val = DP_LINK_BW_5_4;
- /*
* Return an index into ti_sn_bridge_dp_rate_lut. Just hardcode* these indicies since it's not like the register spec is ever going* to change and a loop would just be more complicated. Apparently* the DP sink can only return these few rates as supported even* though the bridge allows some rates in between.*/- switch (data) {
- case DP_LINK_BW_1_62:
return 1;- case DP_LINK_BW_2_7:
return 4;
- switch (dpcd_val) {
- default:
DRM_DEV_ERROR(pdata->dev,"Unexpected max rate (%#x); assuming 5.4 GHz\n",(int)dpcd_val);/* fall through */
return 7;
rate_valid[7] = 1;/* fall through */- case DP_LINK_BW_2_7:
rate_valid[4] = 1;/* fall through */- case DP_LINK_BW_1_62:
rate_valid[1] = 1;break;
- DRM_DEV_ERROR(pdata->dev,
"Unexpected max data rate (%#x); assuming 5.4 GHz\n",(int)data);- return ARRAY_SIZE(ti_sn_bridge_dp_rate_lut) - 1;
}
static void ti_sn_bridge_set_video_timings(struct ti_sn_bridge *pdata) @@ -609,9 +655,9 @@ static int ti_sn_link_training(struct ti_sn_bridge *pdata, int dp_rate_idx, static void ti_sn_bridge_enable(struct drm_bridge *bridge) { struct ti_sn_bridge *pdata = bridge_to_ti_sn_bridge(bridge);
- bool rate_valid[ARRAY_SIZE(ti_sn_bridge_dp_rate_lut)] = { }; const char *last_err_str = "No supported DP rate"; int dp_rate_idx;
- int max_dp_rate_idx; unsigned int val; int ret = -EINVAL;
@@ -655,11 +701,15 @@ static void ti_sn_bridge_enable(struct drm_bridge *bridge) regmap_update_bits(pdata->regmap, SN_SSC_CONFIG_REG, DP_NUM_LANES_MASK, val);
- ti_sn_bridge_read_valid_rates(pdata, rate_valid);
- /* Train until we run out of rates */
- max_dp_rate_idx = ti_sn_bridge_get_max_dp_rate_idx(pdata); for (dp_rate_idx = ti_sn_bridge_calc_min_dp_rate_idx(pdata);
dp_rate_idx <= max_dp_rate_idx;
dp_rate_idx < ARRAY_SIZE(ti_sn_bridge_dp_rate_lut); dp_rate_idx++) {if (!rate_valid[dp_rate_idx])continue;- ret = ti_sn_link_training(pdata, dp_rate_idx, &last_err_str); if (!ret) break;
-- 2.24.1.735.g03f4e72817-goog
Hi,
On Wed, Dec 18, 2019 at 2:36 PM Douglas Anderson dianders@chromium.org wrote:
This series contains a pile of patches that was created to support hooking up the AUO B116XAK01 panel to the eDP side of the bridge. In general it should be useful for hooking up a wider variety of DP panels to the bridge, especially those with lower resolution and lower bits per pixel.
The overall result of this series:
- Allows panels with fewer than 4 DP lanes hooked up to work.
- Optimizes the link rate for panels with 6 bpp.
- Supports trying more than one link rate when training if the main link rate didn't work.
- Avoids invalid link rates.
It's not expected that this series will break any existing users but testing is always good.
To support the AUO B116XAK01, we could actually stop at the ("Use 18-bit DP if we can") patch since that causes the panel to run at a link rate of 1.62 which works. The patches to try more than one link rate were all developed prior to realizing that I could just use 18-bit mode and were validated with that patch reverted.
These patches were tested on sdm845-cheza atop mainline as of 2019-12-13 and also on another board (the one with AUO B116XAK01) atop a downstream kernel tree.
This patch series doesn't do anything to optimize the MIPI link and only focuses on the DP link. For instance, it's left as an exercise to the reader to see if we can use the 666-packed mode on the MIPI link and save some power (because we could lower the clock rate).
I am nowhere near a display expert and my knowledge of DP and MIPI is pretty much zero. If something about this patch series smells wrong, it probably is. Please let know and I'll try to fix it.
Changes in v3:
- Init rate_valid table, don't rely on stack being 0 (oops).
- Rename rate_times_200khz to rate_per_200khz.
- Loop over the ti_sn_bridge_dp_rate_lut table, making code smaller.
- Use 'true' instead of 1 for bools.
- Added note to commit message noting DP 1.4+ isn't well tested.
Changes in v2:
- Squash in maybe-uninitialized fix from Rob Clark.
- Patch ("Avoid invalid rates") replaces ("Skip non-standard DP rates")
Douglas Anderson (9): drm/bridge: ti-sn65dsi86: Split the setting of the dp and dsi rates drm/bridge: ti-sn65dsi86: zero is never greater than an unsigned int drm/bridge: ti-sn65dsi86: Don't use MIPI variables for DP link drm/bridge: ti-sn65dsi86: Config number of DP lanes Mo' Betta drm/bridge: ti-sn65dsi86: Read num lanes from the DP sink drm/bridge: ti-sn65dsi86: Use 18-bit DP if we can drm/bridge: ti-sn65dsi86: Group DP link training bits in a function drm/bridge: ti-sn65dsi86: Train at faster rates if slower ones fail drm/bridge: ti-sn65dsi86: Avoid invalid rates
drivers/gpu/drm/bridge/ti-sn65dsi86.c | 259 +++++++++++++++++++++----- 1 file changed, 216 insertions(+), 43 deletions(-)
Happy New Year everyone!
I know people probably were busy during the last few weeks (I know I was offline) and are now probably swamped with full Inboxes. ...but I'd be super interested if folks had any comments on this series. Notably it'd be peachy-keen if Bjorn / Jeffrey had a chance to see if this is happy for any users of sn65dsi86 that they were aware of.
Thanks much! :-)
-Doug
On Wed 18 Dec 14:35 PST 2019, Douglas Anderson wrote:
This series contains a pile of patches that was created to support hooking up the AUO B116XAK01 panel to the eDP side of the bridge. In general it should be useful for hooking up a wider variety of DP panels to the bridge, especially those with lower resolution and lower bits per pixel.
The overall result of this series:
- Allows panels with fewer than 4 DP lanes hooked up to work.
- Optimizes the link rate for panels with 6 bpp.
- Supports trying more than one link rate when training if the main link rate didn't work.
- Avoids invalid link rates.
It's not expected that this series will break any existing users but testing is always good.
To support the AUO B116XAK01, we could actually stop at the ("Use 18-bit DP if we can") patch since that causes the panel to run at a link rate of 1.62 which works. The patches to try more than one link rate were all developed prior to realizing that I could just use 18-bit mode and were validated with that patch reverted.
These patches were tested on sdm845-cheza atop mainline as of 2019-12-13 and also on another board (the one with AUO B116XAK01) atop a downstream kernel tree.
This patch series doesn't do anything to optimize the MIPI link and only focuses on the DP link. For instance, it's left as an exercise to the reader to see if we can use the 666-packed mode on the MIPI link and save some power (because we could lower the clock rate).
I am nowhere near a display expert and my knowledge of DP and MIPI is pretty much zero. If something about this patch series smells wrong, it probably is. Please let know and I'll try to fix it.
Thanks for the patches Doug, this fixes the rate and DP lane-count issues I'm seeing on my Lenovo Yoga C630 with the current implementation.
Tested-by: Bjorn Andersson bjorn.andersson@linaro.org
Regards, Bjorn
Changes in v3:
- Init rate_valid table, don't rely on stack being 0 (oops).
- Rename rate_times_200khz to rate_per_200khz.
- Loop over the ti_sn_bridge_dp_rate_lut table, making code smaller.
- Use 'true' instead of 1 for bools.
- Added note to commit message noting DP 1.4+ isn't well tested.
Changes in v2:
- Squash in maybe-uninitialized fix from Rob Clark.
- Patch ("Avoid invalid rates") replaces ("Skip non-standard DP rates")
Douglas Anderson (9): drm/bridge: ti-sn65dsi86: Split the setting of the dp and dsi rates drm/bridge: ti-sn65dsi86: zero is never greater than an unsigned int drm/bridge: ti-sn65dsi86: Don't use MIPI variables for DP link drm/bridge: ti-sn65dsi86: Config number of DP lanes Mo' Betta drm/bridge: ti-sn65dsi86: Read num lanes from the DP sink drm/bridge: ti-sn65dsi86: Use 18-bit DP if we can drm/bridge: ti-sn65dsi86: Group DP link training bits in a function drm/bridge: ti-sn65dsi86: Train at faster rates if slower ones fail drm/bridge: ti-sn65dsi86: Avoid invalid rates
drivers/gpu/drm/bridge/ti-sn65dsi86.c | 259 +++++++++++++++++++++----- 1 file changed, 216 insertions(+), 43 deletions(-)
-- 2.24.1.735.g03f4e72817-goog
On 18/12/2019 23:35, Douglas Anderson wrote:
This series contains a pile of patches that was created to support hooking up the AUO B116XAK01 panel to the eDP side of the bridge. In general it should be useful for hooking up a wider variety of DP panels to the bridge, especially those with lower resolution and lower bits per pixel.
The overall result of this series:
- Allows panels with fewer than 4 DP lanes hooked up to work.
- Optimizes the link rate for panels with 6 bpp.
- Supports trying more than one link rate when training if the main link rate didn't work.
- Avoids invalid link rates.
It's not expected that this series will break any existing users but testing is always good.
To support the AUO B116XAK01, we could actually stop at the ("Use 18-bit DP if we can") patch since that causes the panel to run at a link rate of 1.62 which works. The patches to try more than one link rate were all developed prior to realizing that I could just use 18-bit mode and were validated with that patch reverted.
These patches were tested on sdm845-cheza atop mainline as of 2019-12-13 and also on another board (the one with AUO B116XAK01) atop a downstream kernel tree.
This patch series doesn't do anything to optimize the MIPI link and only focuses on the DP link. For instance, it's left as an exercise to the reader to see if we can use the 666-packed mode on the MIPI link and save some power (because we could lower the clock rate).
I am nowhere near a display expert and my knowledge of DP and MIPI is pretty much zero. If something about this patch series smells wrong, it probably is. Please let know and I'll try to fix it.
Changes in v3:
- Init rate_valid table, don't rely on stack being 0 (oops).
- Rename rate_times_200khz to rate_per_200khz.
- Loop over the ti_sn_bridge_dp_rate_lut table, making code smaller.
- Use 'true' instead of 1 for bools.
- Added note to commit message noting DP 1.4+ isn't well tested.
Changes in v2:
- Squash in maybe-uninitialized fix from Rob Clark.
- Patch ("Avoid invalid rates") replaces ("Skip non-standard DP rates")
Douglas Anderson (9): drm/bridge: ti-sn65dsi86: Split the setting of the dp and dsi rates drm/bridge: ti-sn65dsi86: zero is never greater than an unsigned int drm/bridge: ti-sn65dsi86: Don't use MIPI variables for DP link drm/bridge: ti-sn65dsi86: Config number of DP lanes Mo' Betta drm/bridge: ti-sn65dsi86: Read num lanes from the DP sink drm/bridge: ti-sn65dsi86: Use 18-bit DP if we can drm/bridge: ti-sn65dsi86: Group DP link training bits in a function drm/bridge: ti-sn65dsi86: Train at faster rates if slower ones fail drm/bridge: ti-sn65dsi86: Avoid invalid rates
drivers/gpu/drm/bridge/ti-sn65dsi86.c | 259 +++++++++++++++++++++----- 1 file changed, 216 insertions(+), 43 deletions(-)
Applied to drm-misc-next
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